A charger may charge an apparatus such as an electric aircraft, a robot and the like using power supplies such as power lines, batteries, etc. The apparatus is typically charged by a socket connected to the power lines and a charger including a plug and a charging circuit. The charger may be a separate unit or an unit integral to the apparatus such as an aircraft, a robot and the like. The charger may be inserted into a jack of the socket by stretching and retracting the plug, so as to charge the apparatus.
The existing charging technologies have been well developed for stable charging at a relatively low cost. However, in a scenario where the apparatus such as an aircraft, a robot and the like is to be charged automatically, if the conventional plug and socket are used, the apparatus such as an aircraft, a robot and the like may have to precisely recognize a position of the socket, the jack and the plug, demanding significant calculating power and a higher cost. In addition, the algorithm may be complex to implement.